SERVER HARDWARE AND SOFTWARE

The tasks that the machine performs define a server, not the hardware itself. The location and spatial requirements of servers also vary. A small operation may serve its needs with a desktop computer. You will also see small racks or huge racks with hundreds of servers rarely touched by human hands. Fundamentally, the server is a computer that is attached to the Internet and can run the required software.
Basically, the hardware end of the Web servers is just a computer-any ‘box’ will do. The brains and grunt work of Web services takes place on the software side. The requirements of the software determine how powerful the box needs to be. Common examples of server software include Microsoft Internet Information Server (IIS), Apache Web Server, or iPlanetWeb server.
Server software must be compatible with the operating system platform of the computer it’s running on, and Web server software comes bundled together with the box. For example, the Apache Web Server program would not run on a machine with the NT operating system, but you could run it on Red Hat Linux Professional or the Solaris 8 Operating Environment. Microsoft IIS runs with the Microsoft Windows 2000 Advanced Server of NT.
The distinction should be obvious from reading about Internet protocols. One function of Web server software is to recognize the ‘dumbed-down’ packets traveling the Internet and to translate these messages into instructions to be executed. Web server software responds when its IP address is called on. It monitors traffic and provides the glue that connects your website to the outside world. In addition, many websites demand more than simply serving up static Web pages. Among the functions that Web server software may perform are verifying credit cards, registering users, and creating database records. To achieve more sophisticated functionality, specialized server applications have emerged for customized tasks, beyond simply serving up Web pages or connecting to a database

CONNECTED DATABASES
Web developers often talk about performing a function ‘on the back end,’ which means on the Web server (rather than on the user’s browser). The most common function performed on the back end is interactivity with a database. Interaction with a backend database delivers a qualitative jump in the capabilities of a website. All sorts of functions can be delivered that otherwise would be economically unfeasible, if not impossible.
For example, imagine a music website that categorizes bands by type of music, showing a page for each band, all of which are identical except for the specifics of that band. You might use static pages, creating long lists of the bands in each category, and individual pages for each band (Figure 2.4). This manual approach might work fine for 10, 20, maybe even 50 bands. But what happens when you’re ready to go to the next level? Would the process work for a website featuring thousands of bands? Not very efficiently. Creating, maintaining, and testing so many individual pages would give you headaches and bust your budget in no time.
With a backend database, you could grow your band website with ease. Your standardized categories of information about each band would consist of records in the database. When a user picks a particular band, the server software queries the database, and the appropriate data flow into a master template on the site. Your job would be to populate the database, and fill-in forms would make this task easy. Scalability is a key consideration in website design, and databases can provide it. On the user’s end, a database would allow more reliable searching than a static Web site. Users search for bands playing country music or another favorite type of music. The search function is merely a query on a database, and the server software is the engine behind it.